1. Technical Field
This invention relates to hand tools, and more specifically to a hand tool used for crimping clips of a specific configuration which are used for joining sections of sheet metal fabrication, one to the other.
2. Background
A variety of articles of manufacture are fabricated by cutting, bending and otherwise forming sheet metal. Duct work for heating, ventilating and air conditioning purposes is often times fabricated from sheet metal. Typically, sections having a variety of configurations and dimensions are prefabricated in a shop setting where the prefabrication can be done more easily, more efficiently and more cost effectively. The sections of fabricated sheet metal are then transported to the job site where they are to be installed. The prefabricated sections are set in place, typically by hanging or otherwise supporting the sections. The sections are then joined one to another, forming a completed system.
A number of methods have been utilized for joining fabricated sections of sheet metal, including screwing, welding and fastening by a variety of mechanical means. One method of joining the prefabricated sections involves forming a flange at the ends of the sheet metal fabrications which are to be joined. The flanges are then butted one up against another and secured by a mechanical clip known as a TDC clip. The TDC clip is a mechanical connector formed of sheet metal and is secured to the pair of flanges by hooking a lip formed on the clip under the edge of the first flange and forcing, by a lever action, the clip over the outside edge of the second flange. The clip is formed in such a way that it is approximately 6" long having a first leg with a lip for grabbing the outside edge of the first flange. Opposite the clip lip is a longer second leg. The clip first and second legs are joined together by a bridge section. Once the clip is placed over the two flanges as described above, the second leg is crimped, securing the clip in place, joining the flange sections.
The TDC clip is installed with two separate operations: First, an installation or positioning procedure wherein the clip is snapped over the outside edges of the adjoining flanges, and second, a crimping operation wherein the second leg of the clip is crimped to secure the connector into place.
These operations or procedures have been accomplished by the use of two separate tools. First, a placement tool having a cross-sectional configuration corresponding to the cross-sectional configuration of the TDC clip. The placement tool has a lip which secures the clip for placement over the outside edge of the first flange. The placement tool further comprises a lever means for levering the clip over the outside edge of the second flange. Once this operation is complete, the placement tool is removed and a separate crimping tool is used for crimping the leg of the TDC clip to complete the operation. The crimping tool presently used is configured such that it allows crimping only at one point at a time, and the installer must start at one end of the clip, crimping along the full length of the clip.
What is needed is a single tool which can accomplish both the installation and the crimping functions which are presently performed using two separate tools. Such a tool would have the advantage of allowing for quicker and more efficient installation of the TDC clips, and therefore the sheet metal duct work itself. Additionally, such a tool would provide the advantage of eliminating one tool from the sheet metal worker's already overcrowded tool belt.
Finally, the present invention would also have the advantage of providing for a quicker and more consistent installation of the TDC clip, thereby increasing the overall quality of the installation job.